CYPRESS, Texas (AP) — A man accused of stabbing more than a dozen people at a suburban Houston community college chose his victims at random, authorities said Wednesday, going from one floor to another as he used a razor utility knife to slice people in the neck and face.

Neighbors and the grandmother of Dylan Quick were at a loss to explain the attack on the Lone Star Community College campus in Cypress — an attack that authorities say the 20-year-old had fantasized about for years. All 14 of the people who were injured were expected to recover.

“To me he’s just always been a good kid, loving. He’s close to his family. He’s close to his mother and father,” Dolores Quick, his 85-year-old grandmother, said in a telephone interview from her home in Dearborn, Mich. “It’s just really torn me up. I’m just so sad for everybody.”

She said she doesn’t see her grandson on a regular basis, but that she talked to him on the phone every so often.

Officials at the school and people who lived in Quick’s middle class neighborhood described him as well-liked and friendly, but also withdrawn.

Harris County Sheriff Adrian Garcia said while Quick has been cooperative and forthcoming with investigators, the motive for the attack was still a mystery.

“He has shared with us that he’s had fantasies about stabbing people since the age of 8,” Garcia said. “He did share that he had been planning this event for some time.”

Classes resumed Wednesday at the bustling campus where more than 18,000 students take courses. Students and others were overheard talking about the attack, riveted by the sequence of events that left 14 injured, two critically. Students said workers were seen Wednesday morning washing away blood stains from outside the school’s health science building.

Campus President Audre Levy said Quick had worked on the school’s library for about a year and that “the library staff had fond things to say of him” and that many of the library staff were “very surprised” by the allegations.

“There are no signs that he was a problem student. Many of the faculty who had him reported he was a good student,” she said.

The attack took place on the first and second floors of the health science building, but investigators weren’t yet certain on which floor it began. They were working Wednesday to piece together the sequence of events.

Quick slashed at his victims with a razor utility knife, and prosecutors said a scalpel was found in his backpack. A bloody knife tip was removed from the chest of one of the victims, according to prosecutors.

All but two of the victims had been released from local hospitals by Wednesday.

Levy said college police were notified of the attack at 11:13 a.m. Tuesday and that Quick was taken into custody at 11:17 a.m. Authorities said students assisted by tackling Quick and holding him down outside the health science building until police arrived.

Quick remained in custody Wednesday and a spokeswoman with the Harris County district attorney’s office said no additional charges were expected. She said Quick has been ordered to undergo a psychological evaluation.

Court records did not list an attorney for Quick, and his parents did not return several phone calls Wednesday seeking comment.

Michael Lincoln, who lives next door to Quick and his parents, recalled borrowing a ladder from the family in January so he could remove some branches that had fallen on his roof after a storm. Quick lent him the ladder but then proceeded to use it to remove the branches himself, saying, “That’s what neighbors are for,” according to Lincoln.

“I never would have expected (the attack) from him. I guess you never really know anybody,” Lincoln said.

Dolores Quick said she had spoken with her son, Dylan Quick’s father, earlier this week and he had indicated that the family members “were all OK.”